Hydrazinolysis of lipids and analysis of their constituent fatty acids

Treatment of O-acyl lipids with hydrazine degrades them to hydrazides of the constituent fatty acids. These hydrazides react with acetone to yield less polar and more volatile N'-isopropylidenealkanohydrazides, R-CO-NH-N = C(CH3)2, which strongly absorb ultraviolet light and are amenable to thin-layer and gas-liquid chromatographic analyses. In presence of cyclopentene, reduction of double bonds in unsaturated fatty acids with hydrazine does not occur. The method of hydrazinolysis followed by acetonization has been used for fatty acid analysis of different classes of lipids.